NEW YORK (Reuters Health) - Fueling recent criticism of educational DVDs for toddlers, a new study finds that kids do not improve language skills after viewing one such product, the Baby Wordsworth from the Walt Disney Company's Baby Einstein series.

While The Baby Einstein Company does not explicitly make educational claims, it notes on its web page that the Baby Wordsworth DVD is a "playful introduction to words and sign language."

The new study, published in the Archives of Pediatrics & Adolescent Medicine, put the DVD to the test in a group of one- and two-year-olds.

For six weeks, 88 children were randomly assigned to either watch it a few times a week or not at all. Researchers then tested the language skills in each group based on how many words the kids knew according to their parents and how well they did in a lab test.

At the end of the period, toddlers who had watched the DVD fared no better than those who hadn't.

Children in both groups understood about 20 of the 30 words highlighted in the DVD, on average, and spoke 10. Their general language development showed no difference, either.

The researcher also asked parents about their kids' television viewing before entering the study. The earlier a child started watching Baby Einstein DVDs, it turned out, the smaller his or her vocabulary was.

The finding is in line with earlier research, said Rebekah Richert, a psychologist at the University of California, Riverside, who led the study. But it is unclear if the DVDs themselves are responsible. Parents who place their kids in front of the screen could be trying to remedy slow language development, or they could be using the DVDs as baby sitters, cutting back on social stimulation.

"A lot of children, particularly when they're young, seem to have these kinds of (DVDs)," Richert told Reuters Health. "My take-home message would be to encourage live interaction between parent and child."

Although it is not well understood how watching television affects language, Richert and colleagues write in their report, the American Academy of Pediatrics recommends that children younger than 2 stay away from the screen.

Some experts have even suggested that baby videos might be harmful. In a study of several educational DVDs -- including Baby Einstein products -- researchers noted last December that the DVDs "could potentially impede social and cognitive learning."

"Most of the videos were rapidly paced, filled with lots of changes in time and place that will be quite difficult for infants and toddlers to understand," Dr. Sandra L. Calvert from Georgetown University in Washington, D.C., told Reuters Health at the time.

The Baby Einstein Company emphasized in an e-mail to Reuters Health that it "does not claim educational outcomes."

On its web page, it notes that its products "are not designed to make babies smarter," but rather "to engage babies and provide parents with tools to help expose their little ones to the world around them."

"When used properly," the company writes, "developmentally-appropriate video content can be a useful tool for parents and little ones to enjoy together."

Although the company notes that it disagrees with the recommendation from the American Academy of Pediatrics, it does not specify what "proper" use means.